The purpose of this research is to determine the feasibility of a unique eye-tracking concept for controlling assistive devices. This access method may be exceptionally tolerant of head movement and can theoretically determine where the eye is targeted on a computer display to within +/- 0.3 inches. It does not require active devices to be mounted to the user. [unreadable] The system combines a unique contact lens and infrared tracking system to measure where a person is looking. The mathematical approach is computationally simple and efficient, opening the possibility that the system will be reasonably priced for the target population. [unreadable] The proposed eye-tracking system is specifically designed to meet the technology access needs of persons who presently have few or no access options, such as individuals with high spinal-cord injuries, brainstem strokes, or those who are in the late stages of degenerative diseases such as amyotrophic lateral sclerosis. This is accomplished by developing a reasonably priced, practical eye-controlled access method for augmentative communication devices, environmental control units, and computers [unreadable] [unreadable]